Nice KA. Buy an InJen intake from eBay. In all my experience, the best mod that I have done was honestly the VLSD. The driving impression was remarkable. It's the cheapest way to shave massive time off your 0-60 too. You can do that for like $300 from eBay as well. What you need is a 6-bolt output shaft VLSD, like the one that came on the 95 and up J30. Mine is from a J30.
Well, you said engine mods, so think about a top mount T04E, 24" FMIC, 38mm external wastegate, BOV, 3" exhaust, Supra TT injectors, SAFC-II, Z32 fuel pump, Z32 fuel filter, Z32 MAF, and a really tight clutch...